#!/usr/bin/perl

use strict;
use threads;
use Thread::Queue;

my $q = Thread::Queue->new();
for (1..3) {
    $q->enqueue('A' x 100);
    threads->new(\&ttest)
}
my @threadlist = threads->list;
sleep 100;
$q->enqueue(undef) for @threadlist;
$_->join for @threadlist;

sub ttest {
    while (my $item = $q->dequeue) {
        my $cnt = $q->pending;
        print "$cnt\n";
        $q->enqueue('A' x 100);
    }
}